Networking: Safety instrumented systems for processes via fieldbus?
The idea of using fieldbus architecture for safety devices in discrete manufacturing is well established, but so far, process plants have not had this option available. That may be changing as the Fieldbus Foundation has launched a program of end-user testing and pilot plants to demonstrate and prove fieldbus based Safety Instrumented Functions (SIF). Shell, Saudi Aramco, BP, and Chevron are all operating on-site demonstration labs. Shell (Amsterdam) and Saudi Aramco (Dhahran) are the first to have committed to moving the technology into actual plant use once the testing phase is complete.
FOUNDATION Fieldbus has proven well adapted to SIF. The group says no changes were required to the existing protocol to add SIF extensions. These field demonstrations will not only prove the technology, but also promote its adoption in process industries and begin compiling best practices for end users.
A group of companies is participating with Fieldbus Foundation and the operating partners in this effort, including:
Emerson Process Management;
Honeywell Process Solutions;
Westlock Controls; and,
“Our SIF project continues to gain momentum as leading automation equipment suppliers and end users lend their support to developing Foundation solutions for standards-based safety instrumented functions,” says David Glanzer, director of technology development. “We are pleased that a growing list of major users has agreed to take part in our technology demonstration. By extending Foundation technology into safety instrumented functions, they see the opportunity for additional economic benefits of its native predictive diagnostics.”
The SIF protocol meets the rigorous requirements of IEC 61508 standard for functional safety of systems up to SIL 3. In addition, end users can build systems according to IEC 61511 covering SIF for process plants. (IEC 61511 is available as ANSI/ISA-84.00.01-2004.)
—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com ,
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